There has been proposed an apparatus that displays information for recognizing a different vehicle around a host vehicle. To distinctively indicate a host vehicle and a different vehicle, for example, the apparatus disclosed in Patent document 1 displays the different vehicle around the host vehicle in an alarm color, blinks the different vehicle, reverses its color, or displays the host vehicle in blue and the different vehicle in red.
The apparatus described in Patent document 1 displays only a different vehicle, which is present within a specified range or a display frame from the host vehicle, at a position where the different vehicle is located. Accordingly, the apparatus cannot display a different vehicle outside of the display frame. However, a different vehicle might be running fast even if it is distant or remote from the host vehicle and is outside of the display frame. Careful attention must be also paid to the different vehicle. To that end, the display scale may be changed to display the different vehicle distant or remote from the host vehicle within the display frame. However, occasionally changing the display scale makes it difficult to estimate or measure the distance or the angle between the host vehicle and the different vehicle.